And we still use the OEM fuel filter for the diesel.
1998. This is a bit confusing for the uninformed. Officially there is no 1998 model year for the Heavy Duty Ford F-250-F-550 Series Pickup. This was the year that ford went to two different platforms for its trucks- The light duty F-150 and the New Super Duty series of heavy duty work truck available as the F-250 up to F-550. Diesels were not available in the light duty F-150. Where this conversation is about diesel, we will only focus on the Super Duty platform. So if there was no 1998 MY, what was available in 1998? You had a few options. You could buy a 1997 OBS truck(Old Body Style) or the All New Early 1999 MY(Model Year) Super Duty. There were however 1998 MY E-series vans with the Powerstroke diesel. The 1998 E-series had the same updated Powerstroke engine that the 1999-2003 Super Duty would get with the electric lift pump.
1999-2003. These are among the Best, most reliable and heavy duty pickup trucks ever made. Ever. The Crew cab can fit a family of 6 easily. Even if they are 6’6” tall! The cabin space is simply perfect. The drive train is nearly bullet proof save for the transmission. And the 7.3? Well it really became something special during these years. The 7.3 has proven to be exceptionally reliable, and nearly indestructible, so long as you are not trying to make 500hp with them. The truck was released in 1998 as a 1999 model, but there are really two generations of 1999. There is the Early 99, made prior to 12/98, and then the late 99. The differences are subtle, but many. On the engine the Turbo is smaller, the intake is smaller, the turbo pedestal is different, The HPOP is different, Suspension is different, and some of the interior options are different. The trucks are most easily identified by the location of the powerstroke badge. The early 99’s have the “V8 Powerstroke” badge on the Front fender, and the late 99-03 7.3 have the Powerstroke badge on the door. Generally speaking the late 99 trucks are more desirable to have, and the conversion process is slightly easier. In 2002 The Super Duty got clear headlights, a significant change in wiring and Gages, and finally ALL super Duty’s (except the Excursion) got a real Dana 60 Front differential instead of the half breed Dana 50. The engine remains unchanged.
Fuel Delivery. Beginning in 1998 with the E-series Van and in 1999 with the Super Duty trucks, Ford went with an electric lift pump and a deadhead fuel design. The path of fuel flow is from the tank, through the electric lift pump on the frame under the drivers seat, to the Fuel bowl in the engine valley, through a simple poppet regulator, and back to the tank. This causes the fuel bowl to pressurize, forcing fuel through the filter, and out the two fuel lines on the passenger side of the fuel bowl to the OEM fuel feed ports on the engine. One feeds to the Passenger side rear(cylinder 7), the other to the Drivers side front(cylinder 2). The opposite ends of the fuel ports that was used on the earlier years has been plugged off. That means that fuel is only fed to the engine, but never returns from the engine. Tidbit- Factory spec for the fuel pressure is 54psi plus or minus 3. Typically I see anywhere from 60-70 psi on most trucks. But remember from earlier, anything north of 50 and south of 100 is adequate. This fuel system design while simple, had it’s drawbacks as well. Mainly in that the firing order is 1,2,7,3,4,5,6,8. If you remember from earlier, the cylinder arrangement on the drivers side is 2,4,6,8, and fuel is fed into the rail by #2. That puts #8 at the “dead” end of the fuel rail. It is getting what fuel is left over from the other cylinders. Then to further complicate matters is that #6 fires immediately before #8. So #6 is further robbing #8 for fuel. This leads to a constant state of fuel starvation for #8. There are a few ways to combat this problem. Ford, devised the so called “Long Lead” injector. This was a futile attempt at incorrectly solving the problem by modifying an injector with a longer filling time. It didn’t work. The aftermarket had some much more effective ways of dealing with this by either shimming the pressure regulator to increase fuel pressure therefore helping to overcome restrictions to flow and allowing more fuel to #8, or the more expensive but better option which was the regulated return. Fuel was fed all the way through the head, and pressure was regulated after the injectors, not before. This ensured a much more stable fuel pressure for ALL injectors and eliminated any starvation issues. This resulted in a much quieter engine, smoother idle, and some gain power, maybe as much as 15hp on an otherwise stock truck. One other issue that was well known was that the Ford fuel system was known for getting air into the fuel either from the fuel line seals between the pump and tank, or from the fuel pickup in the tank itself. This air would get trapped in the heads with nowhere to go but through the injectors. Fortunately the injectors on the 7.3 were very robust, and the fuel starvation or the air did not have any real detrimental effect on the life of the engine or injectors. There are plenty of bone stock 7.3’s with 500,000 miles or more on them. One other item of note that is really only for the horsepower junkies is that in 2001 Ford started using PMR process connecting rods instead of the Forged rods it had been using since 1994. Ideally the PMR rods have a higher tensile strength and greater hardness then the Forged rods, but they were also much more brittle, and when used with an unreinforced crankcase were more prone to breakage than the much more forgiving Forged rods. Rule of thumb is no more than 400hp with PMR’s, and up to 500hp with the Forged.
The End. 2003 would mark the last year that you could buy a Ford truck in the United States with the coveted 7.3 Powerstroke ending a highly successful 10 year run that helped make the Ford Super Duty the undisputed champion of Reliable Hard working trucks. Federal emissions regulations, and increasing HP/TQ demands in the marketplace dictated the need for a newer, smaller, more efficient, more powerful, and more emissions friendly engine. And in 2003, the all new high tech 6.0 Powerstroke was released, becoming one of the biggest black eyes Ford Trucks have ever known.
6.0 Powerstroke. This engine was the future of Diesels. High tech and High Power. The all new 6.0 had Four Valves per cylinder, A variable Vane turbo that could provide maximum boost off idle, smaller more efficient HEUI injectors operating at up to 26,000 psi, Pilot Injection that made the motor super quiet for a diesel. The block was a two piece design now with the crank being held in place by the two halves of the block ensuring an extremely strong and rigid bottom end. And finally the old 4R100, formerly the E4OD that has been around since the 80’s gets replaced with a modern 5 speed automatic made for diesel use, called the 5R110. The 5R110 was better in every way than the outgoing 4R100. These Transmissions had very few issues, if any. The same could not be said for the motor.
Pick your poison. International who designed the 6.0 had already been using them in their fleet fairly successfully. However the consumer light truck market was different than the commercial truck market. Ford didn’t dare release a new engine that couldn’t match or better the competitors HP and TQ numbers. And of course it had to be quieter as well. This required a higher RPM, a different turbo, and modified injectors from the original International design the meet the requirements. The engine had already been through substantial testing and validating, so changing a few items shouldn’t cause much problem.
Last edited by Fordnut74; 09-30-2009 at 07:52 AM.